It has been observed that during injection of a contrast media at high flow rates into a small-sized lumen, the sudden increase in pressure inside the lumen may lead to failure of the catheter wall. In addition, catheters that are implanted in a patient's body for a period of time may have thrombus build-up within the lumen of the catheter. These thromboses may occlude the catheter and cause overpressurization when the catheter is flushed. To prevent the sudden pressure spikes, a pressure buffering component may be provided to modulate the pressure inside the catheter lumen. Various other medical applications that require high throughput fluid injection through a catheter may also benefit from having a pressure modulating device integrated within the catheter to prevent overpressurizing and/or to provide an indicator to the operator that the catheter is being overloaded.
Examples of various overpressure protection devices are disclosed in U.S. Pat. No. 3,543,759, titled “CATHETER WITH SAFETY INDICATOR” issued to McWhorter, dated Dec. 1, 1970; U.S. Pat. No. 4,000,741, titled “SYRINGE ASSEMBLY” issued to Binard et al., dated Jan. 4, 1977; U.S. Pat. No. 4,240,430, titled “SYRINGE ASSEMBLY” issued to Binard et al., dated Dec. 23, 1980; U.S. Pat. No. 4,403,988, titled “SYRINGE ASSEMBLY” issued to Binard et al., dated Sep. 13, 1983; U.S. Pat. No. 4,671,786, titled “OVERPRESSURE SAFETY VALVE” issued to Krug, dated Jun. 9, 1987; U.S. Pat. No. 6,033,393, titled “METHOD AND APPARATUS FOR OVERPRESSURE PROTECTION OF A CATHETER” issued to Balbierz et al., dated Mar. 7, 2000; U.S. Pat. No. 6,520,977 B2, titled “UTERINE BALLOON APPARATUS AND METHOD” issued to Piraka, dated Feb. 18, 2003; each of which is incorporated herein by reference in its entirety.
Many of the devices disclosed above are design for low flow applications. Furthermore, in a pressure protection device that is based on a compliant balloon, the balloon will typically enlarge gradually in response to pressure, and therefore does not provide a clear indication to the operator when a critical pressure threshold has been breached. Thus, in applications where high pressure injections are required, the operators may have difficulty determining whether overpressurization has occurred by observing the condition of a partially inflated balloon alone. In addition, many of these designs may fail at high pressure, such as 300 psi or above. The compliant nature of the pressure protection mechanisms in these devices may also prevent high pressure from being maintained within the catheter, since many of the compliant balloons will start to expand at a relatively low pressure. These designs tend to have a low pressure threshold, and, as a result, the overall fluid throughput is also relatively low. In addition, many of the disclosed devices have flow paths with high flow resistance.
For power injection applications where a high fluid infusion rate is necessary, it may be desirable to have a pressure buffering device that allows one to maintain high pressure, such as 300 psi or above, within the lumen of the catheter, but at the same time is capable of modulating sudden pressure peaks. Sudden pressure spikes due to initial introduction of fluid pressure, unanticipated obstruction within the catheter, or operator error, may temporarily force the pressure inside the catheter to exceed the breaking threshold (i.e., burst value) of the catheter. However, for high flow rate injection a relatively high pressure needs to be maintained within the catheter to maintain the high throughput. Thus, a device that can prevent pressure spikes and overpressurization, but at the same time allows the system to maintain a relatively high pressure within the catheter to support high flow rate application may be desirable.
In addition, it may be desirable to have a catheter that can be configured with a low resistance flow path to maximize flow rate for power injection applications. A catheter that can be configured to minimize flow resistance and support high fluid flow rate may be particularly useful for power injection applications.